Print current Mac wattage (with accuracy up to minute)

mac-wattage.sh

#!/usr/bin/env bash

set -euo pipefail

function extract_float_field() {
    field=$1
    ioreg -rw0 -c AppleSmartBattery |
        grep BatteryData |
        sed -E "s/.*\"$field\"=([0-9]+).*/\1/" |
        xargs -I % lldb --batch -o "print/f %" | # Convert IEEE-754 float
        grep -o '$0 = [0-9.]*' |
        sed 's/.*= //'
}

printf -- 'Charging (watt): '
extract_float_field AdapterPower

printf -- 'Consumption (watt): '
extract_float_field SystemPower